Ink distribution apparatus

Abstract

Apparatus for distributing ink or other fluid on the surface of a rotating roll in flexographic or gravure type printing equipment. The ink distributing apparatus includes a backplate, first, second and third blades affixed to the backplate and having edges that define points of an arc, a secondary reservoir defined by the backplate and first and second doctor blades, and a primary reservoir defined by the backplate and the second and third doctor blades which is adjacent to the secondary reservoir. Inlets are also provided for communicating a fluid into each reservoir at relatively low pressure. The edges of the blades may be placed in close proximity with a surface of a roll having a periphery corresponding to the arc defined by the blade edges. Thus, the apparatus may be used to distribute a quantity of fluid received within the reservoirs on the surface of the roll when the roll rotates past the apparatus.

What is claimed is: 
     
       1. Apparatus for distributing fluid inks, comprising: a roll having a longitudinal axis of rotation, a cylindrical surface, and a plurality of cells defined in said cylindrical surface for receiving ink;   a backplate disposed parallel to said longitudinal axis and overlying said cylindrical surface of said roll;   first, second and third blades affixed to said backplate generally parallel to said longitudinal axis of said roll, said first, second and third blades extending between said backplate and said cylindrical surface;   said second and third blades having edges in contact with said cylindrical roll surface;   said cylindrical surface, backplate and second and third blades defining a primary reservoir for receiving a quantity of ink and covering at least about 30° of said cylindrical surface of said roll;   said cylindrical surface, backplate and first and second blades defining a secondary reservoir adjacent said primary reservoir for receiving a quantity of ink, said secondary reservoir covering at least about 85° of said cylindrical surface of said roll; and   means for separately charging each said primary and secondary reservoir with pressurized ink, whereby ink within said reservoirs may be distributed on said cylindrical surface of said roll when said roll rotates past said blades, and further whereby the portion of said cylindrical surface that is exposed to ambient conditions is reduced, thereby reducing drying of ink within said cells of said roll.   
     
     
       2. Apparatus as defined in claim 1 wherein said primary and secondary reservoirs cumulatively cover at least about 300° of said cylindrical roll surface. 
     
     
       3. Apparatus as defined in claim 1 wherein said first blade has an edge in contact with said cylindrical roll surface. 
     
     
       4. Apparatus as defined in claim 1 wherein said first blade is inclined toward said secondary reservoir at an angle of between about 38° and 45° relative to a tangent from said cylindrical surface. 
     
     
       5. Apparatus as defined in claim 4 wherein said second blade is inclined toward said primary reservoir at an angle of between about 1520  and 50° relative to a tangent from said cylindrical surface. 
     
     
       6. Apparatus as defined in claim 5 wherein said third blade is inclined toward said primary reservoir at an angle of between about 1020  and 40° relative to a tangent from said cylindrical surface. 
     
     
       7. Apparatus as defined in claim 6 wherein said first blade is inclined at an angle of about 38°, wherein said second blade is inclined an angle of about 25°, and wherein said third blade is inclined an angle of about 25°. 
     
     
       8. Apparatus as defined in claim 6 wherein said means for charging said reservoirs with ink is adapted to charge said reservoirs with ink at a pressure of less than about 3 pounds per square inch. 
     
     
       9. Apparatus as defined in claim 8 further comprising a manifold for evenly distributing fluid ink across each said reservoir. 
     
     
       10. Apparatus as defined in claim 9 wherein said manifold is adapted to charge each said reservoir with ink at a pressure of about 1 psi. 
     
     
       11. Apparatus for distributing fluid inks, comprising; a roll having a longitudinal axis of rotation, a cylindrical surface, and a plurality of cells defined in said cylindrical surface for receiving ink;   a backplate disposed parallel to said longitudinal axis and overlying said cylindrical surface of said roll;   first, second and third blades affixed to said backplate generally parallel to said longitudinal axis of said roll, said first, second and third blades extending between said backplate and said cylindrical surface;   said second and third blades having edges in contact with said cylindrical roll surface;   said cylindrical surface, backplate and second and third blades defining a primary reservoir for receiving a quantity of ink and covering at least about 30° of said cylindrical surface of said roll;   said cylindrical surface, backplate and first and second blades defining a secondary reservoir adjacent said primary reservoir for receiving a quantity of ink;   said primary and secondary reservoirs cumulatively covering at least about 115° of said cylindrical surface; and   a manifold for independently and evenly charging each said primary and secondary reservoir with pressurized ink at a pressure of less than about 3 psi, whereby ink within said reservoirs may be distributed on said cylindrical surface of said roll when said roll rotates past said blades, and further whereby the portion of said cylindrical surface that is exposed to ambient conditions is reduced, thereby reducing drying of ink within said cells of said roll.   
     
     
       12. Apparatus as defined in claim 11 wherein said primary and second reservoirs cumulatively cover at least about 300° of said cylindrical surface. 
     
     
       13. Apparatus as defined in claim 12 wherein said first blade is inclined toward said secondary reservoir at an angle of between about 38° and 45° relative to a tangent from said cylindrical surface, wherein said second blade is inclined toward said primary reservoir at an angle of between about 15° and 50° relative to a tangent from said cylindrical surface, and wherein said third blade is inclined toward said primary reservoir at an angle of between about 10° and 40° relative to a tangent from said cylindrical surface. 
     
     
       14. Apparatus as defined in claim 13, wherein said first blade is inclined at an angle of about 38°, wherein said second blade is inclined an angle of about 25°, and wherein said third blade is inclined an angle of about 25°. 
     
     
       15. Apparatus for distributing fluid inks, comprising: a roll having a longitudinal axis of rotation, a cylindrical surface, and a plurality of cells defined in said cylindrical surface for receiving ink;   a backplate disposed parallel to said longitudinal axis and overlying said cylindrical surface of said roll;   first, second and third blades affixed to said backplate generally parallel to said longitudinal axis of said roll, said first, second and third blades extending between said backplate and said cylindrical surface;   said second and third blades having edges in contact with said cylindrical roll surface;   said cylindrical surface, backplate and second and third blades defining a primary reservoir for receiving a quantity of ink and covering at least about 30° of said cylindrical surface;   said cylindrical surface, backplate and first and second blades defining a secondary reservoir adjacent said primary reservoir for receiving a quantity of ink;   said adjacent primary and secondary reservoirs cumulatively covering at least about 300° of said cylindrical surface of said roll; and   a manifold for independently charging each said primary and secondary reservoir with pressurized ink at a pressure of about 1 psi, whereby ink within said reservoirs may be distributed on said cylindrical surface when said roll rotates past said blades, and further whereby the portion of said cylindrical surface that is exposed to ambient conditions is reduced, thereby reducing drying of ink within said cells of said roll.   
     
     
       16. Apparatus as defined in claim 15 wherein said first and third blades have edges in contact with said cylindrical surface. 
     
     
       17. Apparatus as defined in claim 15 wherein said first blade is inclined toward said secondary reservoir at an angle of between about 38° and 45° relative to a tangent from said cylindrical surface, wherein said second blade is inclined toward said primary reservoir at an angle of between about 15  and 50° relative to a tangent from said cylindrical surface, and wherein said third blade is inclined toward said primary reservoir at an angle of between about 10° and 40° relative to a tangent from said cylindrical surface. 
     
     
       18. Apparatus as defined in claim 17, wherein said first blade is inclined at an angle of about 38°, wherein said second blade is inclined an angle of about 25°, and wherein said third blade is inclined an angle of about 25°.